Here again my mom wants me to do math and I’m not that smart

Guests at an amusement park must be at least 54 inches tall to be able to ride the roller coaster. which graph represents the set of heights that satisfy this requirement?

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much